摘要
随着电动汽车的发展,迫切需要具有高安全性、高能量密度、高功率、大容量、长寿命、高环保、低成本等优点的锂离子电池。层状结构的富锂锰基正极材料由于具有比容量高、平台电压高、热稳定性好、价格低廉的特点而被认为是有希望的未来电动汽车候选正极材料之一。尽管其拥有很高的比容量,但仍存在着首次循环不可逆容量高、倍率性能差等问题,纳米化是改进材料倍率性能的一种有效手段。本文以Ni O,Co_3O_4,Mn CO_3和Li_2CO_3为原料,成功制备得到了纳米级的锂离子电池正极材料Li_(1.2)Ni_(0.13)Co_(0.13)Mn_(0.54)O_2。通过X射线衍射(XRD)、扫描电子显微镜(SEM)和充放电测试对所得样品的结构、形貌及电化学性能进行了表征。结果表明,合成的Li_(1.2)Ni_(0.13)Co_(0.13)Mn_(0.54)O_2材料具有层状结构,一次颗粒均匀、细小,平均颗粒尺寸约为90 nm,并具有良好的电化学性能,在2.0~4.8 V以0.1C充放电时,首次放电比容量达到284 m Ah·g^(-1),首次库伦效率为86.1%。材料同时拥有良好的倍率性能,1.0C放电容量达到240 m Ah·g^(-1),3.0C放电容量达到210 m Ah·g^(-1)。
With the development of electric vehicles, it is urgent to develop lithium-ion battery with high safety, high energy density, high power, high capacity, long lifespan, low-cost and environmental friendliness. The Li-rich, Mn based layered cathode materials exhibit many attractive features such as high capacity, high voltage plateau, good thermal stability and low prices, and are widely re- garded as one of the most promising candidates for future electric vehicles. Despite of their high capacity, these materials show a high first cycle irreversible capacity, poor rate capability and so on. Nanostructuring and the use of cathode nanomaterials offer an effective solution to improve the rate capability. Li1.2Ni0.13Co0.13Mn0.54O2 was synthesized from NiO, Co3O4 , MnCO3 and Li2 CO3 with improved solid state method. The products were analyzed by X-ray diffraetometry （XRD） , scanning electron microscopy （SEM） and electrochemical tests. The resuhs showed that the Li1.2Ni0.13Co0.13Mn0.54O2 material exhibited uniform and nano particle sizes with average size of 90 nm, and had excellent electro-chemical property. The initial discharge capacity of prepared Li1.2Ni0.13Co0.13Mn0.54O2 was 284 mAh g-1 , and coulombic efficiency was 86.1% when charged and discharged at 0.1 C within 2.0 -4.8 V. The material had good rate capability. Its 1.0C rate capability was 240 mAh g-1 , and 3. OC rate capability was 210 mAh g-1.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2016年第1期38-42,共5页
Chinese Journal of Rare Metals
基金
国家科技部高技术研究计划“863计划”项目(2012AA052201)
国家自然科学基金项目(51302017)资助
